The present invention relates to an adjustable isolation sleeve that can be used as a retrofit for existing well completion systems.
Well completion systems include a wellhead, a tree block sometimes called a spool body, and a tubing hanger landed in the spool body. Inside valve through bore systems, the spool body defines a vertical bore extending therethrough and has a horizontal production outlet in flow communication with the vertical bore. The spool body has annular sealing profiles that accommodate annular gaskets at both the top and bottom connections. At the lower sealing connection, a parallel sealing diameter is provided for an isolation sleeve.
The spool body is mounted on the wellhead and has the tubing hanger landed within its vertical bore. The spool body typically has an isolation sleeve attached to the lower end inside the vertical bore. The main function is to seal off against the casing hanger. With the tree landed on the wellhead, the isolation sleeve isolates the annulus from the annular gasket. A test port can be provided to test the interspace between the isolation sleeve and the annular gasket.
The isolation sleeve may also act as an orientation sleeve for the tubing hanger. Orientation can be provided by a helical profile and slot machined into the inside surface of the isolation sleeve. In the alternative, a helix having a slot can be attached to the spool body and positioned inside the isolation sleeve.
In order to properly mate an isolation sleeve with an existing well completion system, the isolation sleeve is required to be a defined length. If the casing hanger height as it is found in the field, is not as per the specifications, traditionally a new isolation sleeve will need to be forged and machined. An isolation sleeve that is adjustable in length allows the operator to adjust the isolation sleeve to the required length in the field, to forego the time and expense of forging and manufacturing a new isolation sleeve.